The significance of different sample types of α-coronavirus for the diagnosis of infectious peritonitis

Recommended	Sample	Diagnostic meaning
*****	Exudate	Positive: FIP is strongly suspected; Negative: FIP cannot be ruled out. Combined with other laboratory indicators, it is highly likely to diagnose FIP.
****	Cerebrospinal fluid	Strongly positive: can be used as a basis for diagnosis (dry FIP); negative: cannot rule out neurological FIP.
**	Aqueous humor	It has good specificity for the diagnosis of FIP (dry FIP).
**	Eye surface cells and tears	This provides good support for the diagnosis, but a negative result cannot rule out FIP.
*	Enlarged mesenteric lymph nodes	It has a good supporting role in the diagnosis of FIP.
*	Diseased tissue in the liver or kidneys	It has a certain supporting role in the diagnosis of FIP but has high requirements for sampling; it is common in dry infectious peritonitis with few organ lesions.
Not	Stool	It cannot be used to diagnose FIP.
Not	Saliva	Not practical, test results are often negative.
Not	Blood	Not practical, most cats with FIP will have negative test results, and even if they are positive, it cannot be used as a diagnosis because clinically healthy cats or cats with other diseases may also have positive PCR results.

Note:

If you want to check for intestinal coronavirus, you can directly collect anal swabs.

If you want to check for intestinal coronavirus, you can directly collect anal swabs.

If you suspect wet peritonitis, it is recommended to collect ascites.

If you suspect dry peritonitis, it is recommended to collect puncture fluid from enlarged lymph nodes in the intestinal system.